The present invention relates to a substrate for a liquid crystal display (LCD) and method for manufacturing same. More particularly, the invention relates to an LCD substrate formed with a bordering buffer film which reduces substrate warping. The present invention also relates to a method for manufacturing the foregoing LCD substrate.
The conventional manufacturing process for LCDs begins with a glass substrate. The glass substrate is cleaned, or "washed," and a matrix of thin film transistors (TFTs) and related pixel elements are formed on the glass substrate by known techniques. A liquid crystal is then injected into a space between the thus fabricated glass substrate structure and an opposing color filter substrate, or similar opposing surface.
of particular note, the conventional glass substrate is flexible to a certain degree. For example, a conventional glass substrate 1 will bow or curve in the middle when carried on edge supports 6, as shown in FIG. 1. The bow shown in FIG. 1 is exaggerated to illustrate the difficulty arising when even slight bowing occurs in the glass substrate. That is, bowing may cause lifting or shifting of the semiconductor layers subsequently formed on the conventional glass substrate. For example, the aluminum film forming the gate electrodes of the TFTs may separate from the substrate and actually create shorts and opens in the electrode paths. Bowing, warping in any direction, may become particularly pronounced in high temperatures applied to the glass substrate during heat treatment steps common to the manufacture of the LCD. As LCDs increase in size, the tendency of the underlying glass substrate to warp under its own weight only increases. The resulting effects of glass substrate warping can be disastrous.